Method, system and device for a network side to enable an mss to enter the idle mode in a wireless man

ABSTRACT

The present invention provides a method as regards how a network side gets a MSS into the idle mode in a wireless MAN, including: the PA/BS sends a DREG_CMD to the MSS; the MSS sends a DREG_REQ message to the PA/BS, according to the DREG_CMD message, requesting to enter the idle mode; the PA/BS releases the link of the MSS and updates the data of the anchor PC/LR, after receiving the DREG_REQ message. The present invention specifies the process of a MSS entering the idle mode initiated by the network and the settings of relevant parameters, thus enhancing the stability of the process of entering the idle mode and saving the system resources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of a U.S. patent application Ser. No.12/260,717, filed Oct. 29, 2008, which is a continuation of theInternational Patent Application No. PCT/CN2007/001484, filed Apr. 30,2007, which claims priority to Chinese Patent Application No.200610075196.6, filed Apr. 30, 2006 and Chinese Patent Application No.200610094437.1, filed Jun. 19, 2006, all of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to the wireless Metropolitan Area Network(MAN) technology, and in particular, to a method for a network side toenable a Mobile Station System (MSS) to enter the idle mode in awireless MAN.

BACKGROUND

The idle mode is a working mode of a terminal in a mobile broadbandRadio Access System (RAS). In the idle mode, a MSS can move in a setarea, and receive the downlink broadcast service messages at regularintervals. The downlink broadcast service messages are designed tonotify the MSS whether any downlink service needs to be transmitted.While roaming in an area, a MSS does not need to get registered on theBase station (BS) of the cell where the MSS is roaming. Meanwhile, whileroaming in different cells, the MSS does not need to perform normaloperation processes, such as handover, which is conducive to saving MSSpower and air interface resources.

Multiple BSs make up a group, called Paging Group (PG). A PG is intendedto constitute a continuous area, inside which the MSS does not need tosend uplink services but can use downlink paging channels to judgewhether any downlink service is sent to the MSS. On one hand, a PG mustbe large enough to ensure that most MSSs are kept in the same PG in along time; on the other hand, a PG must be small enough to ensure thatthe overhead spent by the PG for paging a MSS is reasonable.

In the normal operation process on a Serving BS (SBS), the MSS mayrequest to enter the idle mode by sending a message. Likewise, a servingBS may require an MSS to enter the idle mode by sending a message. Nomatter whether the MSS requests to enter the idle mode through a messageor the serving BS requires the MSS to enter the idle mode through amessage, the MSS must finish deregistration and enter the idle modewithin the specified time.

The Worldwide Interoperability for Microwave Access (WiMAX) standardcurrently under development defines a paging reference model in the idlemode, in which the Paging Controller (PC) is a network entity thatcontrols the activities of a MSS in the idle mode. The PC is a logicentity in the current WiMAX network architecture. Since a PC needs tosend paging messages according to the PG that currently contains theMSS, a Location Register (LR) is required for storing the stateinformation, paging information and service flow information of the MSS.Generally, each LR logic entity corresponds to one PC logic entity, andthe two logic entities work in the same physical Network Element (NE).PCs can be divided into the following two types: (i) anchor PC: each MSSin the idle mode uniquely corresponds to an anchor PC which controls theactions of the MSS in the idle mode and controls the relevant processes;(ii) relay PC: one idle MSS may have one or more relay PCs forcommunicating with the anchor PC. For different MSSs, a PC may act asboth anchor PC and relay PC.

Generally, a Paging Agent (PA) located in a BS is designed to handlepaging and the functions related to the idle mode.

Regardless of other physical Network Elements (NEs) and logic entitiesin the WiMAX network, the following description is made with respect tothe WiMAX paging reference model shown in FIG. 1 (the technical solutionunder the present invention includes, but is not limited to, theapplication in a WiMAX system).

According to the paging reference model shown in FIG. 1, when a MSSrequests to enter the idle mode on the SBS, or the SBS instructs the MSSto enter the idle mode, message interaction will be performed betweenthe MSS and SBS and between the SBS and the back-end NE “ASN GW” tonotify the PC that the MSS enters the idle mode (this is implemented inthe Access Service Network Gateway (ASN GW)). The state information,paging information, and service flow information of the MSS are saved inthe corresponding LR.

FIG. 2 shows the process of entering the idle mode initiated by a MSS.The detailed procedure is as follows:

(1) The MSS sends a deregistration request (DREG_REQ) to the PA/DPF (orPA/SBS for the reason that DPF is located in the SBS);

(2)-(3) The local PC receives the DREG_REQ, specifies an anchor PC forthe MSS, allocates paging parameters for the MSS to enter the idle mode,and then returns such information to the serving PA through a MSS DregRsp message;

(4)-(5) The serving PA uses the functions of its Data Path Function(DPF) entity to send a data path release request (Data Path Rel Req) tothe relay DPF on the MSS link, in order to release the link on the MSS.The relay DPF on the link forwards the Data Path Rel Req to the anchorDPF;

(6) The anchor DPF sends a MSS information request (MSS Info Req)message to the anchor PC specified in the Data Path Rel Req message;

(7) After receiving the MSS Info Req, the anchor PC contacts the anchorauthenticator to verify whether to allow the MSS to enter the idle mode,and replies with a MSS Info Rsp to the anchor DPF;

(8) According to the MSS Info Rsp, the anchor DPF sends a Data Path RelRsp to the relay DPF if the MSS is allowed to enter the idle mode;

(9) The relay DPF sends a Data Path Rel Rsp message to the servingPA/DPF; and

(10) After receiving the Data Path Rel Rsp, the PA/DPF confirms that theMSS enters the idle mode successfully, and sends, from the airinterface, a deregistration command (DREG_CMD) message to the MSS, thusfinishing the process of entering the idle mode.

However, the inventor discovered that the prior art has defects aboutthe process of entering the idle mode initiated by the network; theprior art does not specify the process of the MSS entering the idle modeinitiated by the network, which impairs the stability of the process ofentering the idle mode.

The invention also discovered that the prior art does not consideranother circumstance of entering the idle mode initiated by the network:when the network initiates the process of entering the idle mode, thenetwork cannot enable the MSS to enter the idle mode unless the MSSsends a request of entering the idle mode after a delay of REQ-duration.Moreover, when the network requires the MSS to enter the idle mode, theMSS may require a delay for its own reasons before entering the idlemode.

SUMMARY

The present invention provides a method for a network side to enable aMSS to enter the idle mode in a wireless MAN.

A method for a network side to enable a MSS to enter the idle mode in awireless MAN includes: sending, by a PA/BS, a DREG_CMD message to theMSS; receiving, by the PA/BS, a DREG_REQ message from the MSS,requesting to enter the idle mode; and releasing, by the PA/BS, the linkof the MSS and updating the data of the anchor PC/LR, after receivingthe DREG_REQ message.

The present invention specifies the process of a MSS entering the idlemode initiated by the network and the settings of relevant parameters,thus enhancing the stability of the process of entering the idle modeand saving the system resources.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a paging reference model of a WiMAX system.

FIG. 2 shows the process of entering the idle mode initiated by a MSS.

FIG. 3 shows the process of a MSS entering the idle mode initiated by anetwork, according to an embodiment of the present invention.

FIG. 4 shows the process of a MSS entering the idle mode initiated by anetwork, according to another embodiment of the present invention.

FIG. 5 shows another process of a MSS entering the idle mode initiatedby a network, according to another embodiment of the present invention.

FIG. 6 shows the process of a MSS entering the idle mode initiated by anetwork, according to another embodiment of the present invention.

FIG. 7 shows another process of a MSS entering the idle mode initiatedby a network, according to another embodiment of the present invention.

DETAILED DESCRIPTION

The present invention supports two types of processes in which a networkside enables a MSS to enter the idle mode:

i. when the network side sends a request of getting the MSS into theidle mode, the network entity enables the MSS to enter the idle modedirectly without delay; and

ii. when the network side sends a request of enabling the MSS to enterthe idle mode, the network entity requires the MSS to wait for a periodof time before entering the idle mode.

Moreover, the present invention specifies another scenario. For example,if multiple hosts are attached to a MSS, the MSS may need a period oftime of waiting before entering the idle mode due to interaction withthe host, when the network is initialized to get the MSS into the idlemode. The present invention is hereinafter described in detail withreference to the embodiments in different scenarios.

Scenario 1: FIG. 3 shows the process of a MSS entering the idle modeinitiated by a network side, according to a first embodiment of thepresent invention. As shown in FIG. 3, the process of includes thefollowing steps:

(1) When deciding to let the MSS enter the idle mode, the PA/SBS sends aMSS Info Req message to the relay PC, with the message carrying thefollowing information: indication of the MSS entering the idle mode, MSSID, Idle Mode Retain Information (indicating the information to beretained in the idle mode), BS ID, anchor DPF/FA ID, anchorauthenticator ID, and so on; “/” in the PA/SBS shown in FIG. 3 meansthat the PA and the SBS are located in the same physical NE or boundtogether; the “/” hereinafter has the same meaning;

(2) After receiving the message, the relay specifies an anchor PC ID forthe MSS, allocates the recommended paging parameters (for example, PGID, Paging_CYCLE, Paging_OFFSET, PC ID), and then sends the message tothe anchor DPF/FA, with the recommended paging parameters added into themessage;

(3) After receiving the message, the anchor DPF/FA stores thecorresponding information, and sends a MSS Info Req message to theanchor PC specified in the message. The MSS Info Req message carries theMSS ID, Idle Mode Retain Information, BS ID, recommended pagingparameters, Service Flow ID (SF ID), and anchor authenticator ID, whichare required for the MSS to enter the idle mode;

(4) After receiving the MSS Info Req message, the anchor PC knows thatthe MSS is requested to enter the idle mode according to the content ofthe message. At this time, the anchor PC contacts the anchorauthenticator to verify whether the MSS is allowed to enter the idlemode. If the verification result allows the MSS to enter the idle mode,the anchor PC will reallocate the paging parameters, according to thespecific conditions (for example, the requirements on setting theparameter), and reply with a MSS Info Rsp message. The message carries aMSS ID, the actual paging parameters (including selected PG ID, PagingCycle, Paging Offset), PC ID, and Idle mode authorization indication.Meanwhile, the anchor PC requires the LR to retain the information onthe MSS;

(5) After receiving the MSS Info Rsp, the FA replies with a MSS Info Rspmessage to the relay PC if the idle mode authorization indication allowsthe MSS to enter the idle mode. The message carries a MSS ID, the actualpaging parameters, a PG ID, a PC ID, an idle mode authorizationindication, and so on. After receiving the message, the relay PCforwards the message to the PA/SBS;

(6) After the PA/SBS receives the message, if the idle modeauthorization indication allows the MSS to enter the idle mode, thePA/SBS sends a DREG_CMD message to the MSS from the air interface. Themessage carries an action code “0x05” (which instructs the MSS to enterthe idle mode directly) and the parameter information is specified inthe 802.16e protocol. Meanwhile, the PA/SBS starts the resourceretaining timer;

(7) After receiving the message, the MSS replies with a DREG_REQ messageto the SBS. The message carries an action code “0x02”, indicating thatthe MSS enters the idle mode successfully, and may be in the formatspecified by the 802.16e protocol. The MSS clears the informationrelated to the link and the session, and enters the idle mode;

(8) After the PA/SBS receives the DREG_REQ message from the MSS, itindicates that the MSS enters the idle mode successfully. Therefore, thePA/SBS sends a Data Path Rel Req message to the relay DPF, requesting torelease the data path and connection related to this MSS. The messagecarries the information required for the MSS to enter the idle mode;

(9) The relay DPF forwards the message to the anchor DPF/FA;

(10) The anchor DPF/FA responds to the request message, releases thedata path and replies with a Data Path Rel Rsp message to the relay DPF;and

(11) After receiving the Data Path Rel Rsp message forwarded by therelay DPF, the PA/SBS confirms success of entering the idle mode.Through a relay DPF, the PA/SBS replies with a Data Path Rel Ack messageto the FA, indicating that the MSS enters the idle mode successfully.The relay DPF notifies the relay PC to delete the information on theMSS. Meanwhile, the FA sends a MSS Info Ack message to the anchor PC,confirming completion of the MSS entering the idle mode. The anchor PCfinally finishes data update in the LR. Further, the anchor PC needs tonotify the anchor authenticator to update and retain the information onthe MSS idle state, including the anchor PC ID, anchor DPF ID, andsecurity context information.

When the resource retaining timer times out, the SBS deletes theinformation on the local MSS.

It should be noted that the relay PC is optional in the foregoing step.If the relay PC does not exist, the PA/SBS will communicate with the FAdirectly.

What is described below is a scenario that the MSS does not enter theidle mode until a period of time expires after the network side sends arequest of enabling the MSS to enter the idle mode. As shown in FIG. 4,the process is as follows:

Steps (1)-(5) are the same as the counterpart in the foregoingembodiment, except that in the process, any of the PA/SBS, relay PC/DPF,anchor DPF/FA and anchor PC/LR can decide whether to require the MSS tosend a DREQ_Request message to enter the idle mode after expiry of aREQ_Duration, according to the actual conditions;

(6) After the PA/SBS receives the message, the PA/SBS sends a DREG_CMDmessage to the MSS from the air interface, if the idle modeauthorization indication allows the MSS to enter the idle mode. Themessage carries an action code “0x05” (which instructs the MSS to enterthe idle mode) and the REQ_Duration parameter. The DREG_CMD message mayadopt the format specified in the 802.16e protocol;

(7) After receiving the message, the MSS replies with a DREG_REQ messageto the SBS after expiry of a duration indicated by the REQ_Duration. Themessage carries an action code “0x01,” indicating that the MSS willenter the idle mode. The message may adopt the format specified by the802.16e protocol. The MSS is ready to enter the idle mode;

(8) After receiving the message, the PA/SBS sends a Data Path Rel Reqmessage to the relay DPF on the MSS link through the DPF entity,requesting to release the link of this MSS. The message carries MSS ID,Idle Mode Retain Information, BS ID, recommended paging parameters (forexample, PG ID, Paging Cycle, Paging Offset, PC ID), Access ServiceNetwork Data Path Function ID (ASN-DPF ID), and authenticator ID, whichare required for the MSS to enter the idle mode. Some parameters in themessage are obtained and stored in Steps (1)-(5). The relay DPF on thelink forwards the Data Path Rel Req message to the anchor DPF (namely,the DPF that is located together with the FA);

(9) After receiving the message, the anchor DPF/FA stores thecorresponding information, and sends a MSS Info Req message to theanchor PC specified in the message. The MSS Info Req message carries theMSS ID, Idle Mode Retain Information, BS ID, recommended pagingparameters, Service Flow ID (SF ID), and anchor authenticator ID, whichare required for the MSS to enter the idle mode;

(10) After receiving the MSS Info Req message, the anchor PC knows thatthe MSS requests to enter the idle mode, according to the content of themessage. Since, in Step (4), it is already verified whether to allow theMSS to enter the idle mode, the anchor PC does not perform suchverification again. The anchor PC may select the paging parametersrecommended by the local PC, or reallocate the paging parameters again,according to the specific conditions, and reply with a MSS Info Rspmessage. The message carries a MSS ID, the actual paging parameters(including selected PG ID, Paging Cycle, Paging Offset), PC ID, and anidle mode authorization indication. Meanwhile, the anchor PC requiresthe LR to retain the information on the MSS;

(11) After receiving the MSS Info Rsp, the FA stores the correspondinginformation, such as PC ID, and replies with a Data Path Rel Rsp messageto the relay PC. The response message carries a MSS ID, the actualpaging parameters, a PG ID, a PC ID, and so on. The relay PC on the linkforwards the message to the PA/SBS;

(12) After receiving the Data Path Rel Rsp, the SBS confirms that theMSS enters the idle mode successfully, and replies, from the airinterface, a DREG_CMD message to the MSS. The message carries an actioncode “0x05.” Meanwhile, the PA/SBS starts the resource retaining timer;

Generally, the resource retaining timer must be started, after the SBSsends a REG CMD message (except that the message carries REQ_Duration).The information on the local MSS will be deleted unconditionally whenthe resource retaining timer times out. If the REG CMD message carries aREQ_Duration, the resource retaining timer can also be started, but thetimer needs to be restarted in this step;

(13) After receiving the message, the MSS deletes information related tothe connection and the session; and

(14) Through a relay PC, the PA/SBS replies with a Data Path Rel Ackmessage to the FA, indicating that the MSS enters the idle modesuccessfully. The relay PC deletes the information on the MSS.Meanwhile, the FA sends a MSS Info Ack message to the anchor PC,confirming completion of the MSS entering the idle mode. The anchor PCfinally finishes data update in the LR. Further, the anchor PC needs tonotify the anchor authenticator to update and retain the information onthe MSS idle state, including the anchor PC ID, anchor DPF ID, andsecurity context information. Upon expiry of the resource retainingtimer, the PA/BS deletes the information on the local MSS.

In this embodiment, the network requires the MSS to send a request ofentering the idle mode after waiting for a REQ_Duration. Therefore, inSteps (1)-(5), the FA or relay PC replies to the PA/BS with a MSS InfoRsp message directly, indicating the waiting time of REQ_Duration. ThePA/BS replies to the MSS with a DREG_CMD message. The message carriesthe REQ_Duration parameter and the Action Code “0x05.” After aREQ_Duration expires, the MSS sends a request of entering the idle modeagain. Namely, the actions executed by the FA and the anchor PC can beomitted. If the relay PC or the FA replies to the PA/SBS directly with aMSS Info Rsp message, in Step (10) it is needed to verify whether theMSS is allowed to enter the idle mode.

In the process shown in FIG. 4, the process of storing the MSS contextinformation into the anchor PC is synchronous to the process ofreleasing the data path.

An alternative process of this embodiment is shown in FIG. 5. Unlike thepreceding process, this process separates the transfer of the MSSinformation from the release of the data path; and the MSS informationand paging-related parameters are transferred through MSS Info Req/MSSInfo Rsp messages. The process is briefly described below:

Steps (1)-(3) are the same as the counterpart of the precedingembodiment. The network side decides whether the MSS will send requestof entering the idle mode only after expiry of a REQ_Duration accordingto the actual conditions. If so, the corresponding MSS Info Req messageor MSS Info Rsp message will carry the REQ_Duration parameter;

(4) After receiving the message, the PA/SBS sends a DREG_CMD message tothe MSS. The message carries an action code “0x05” and a REQ_Durationparameter, and may adopt the format specified by the 802.16e protocol;

(5) After receiving the message, the MSS replies with a DREG_REQ messageto the SBS after expiry of a duration indicated by the REQ_Duration. Themessage carries an action code “0x01,” indicating that the MSS willenter the idle mode. The message may adopt the format specified by the802.16e protocol. The MSS is ready to enter the idle mode;

(6) After receiving the DREG_REQ message from the MSS, the PA/SBS sendsa MSS Info Req message to the corresponding relay PC, requesting todetermine whether the MSS is allowed to enter the idle mode;

(7) After receiving the message, the relay PC allocates information tothe MSS, including: PC ID, paging parameters, MSS ID carried in themessage, Idle Mode Retain Information, BS ID, ASN-DPF ID, and anchorauthenticator ID; and sends the information to the anchor PC through aFA, by means of a MSS Info Req message;

(8) After receiving the MSS Info Req message, the anchor PC knows thatthe MSS requests to enter the idle mode, according to the content of themessage. At this time, the anchor PC contacts the anchor authenticatorto verify whether the MSS is allowed to enter the idle mode. If theverification result allows the MSS to enter the idle mode, the anchor PCwill reallocate the paging parameters, according to the specificconditions (for example, the requirements on setting the parameter), andreply with a MSS Info Rsp message to the PA/SBS. Meanwhile, the anchorPC requires the LR to retain the information on the MSS;

(9) After receiving the MSS Info Rsp message, the PA/SBS replies to theMSS with a DREG_CMD message, starts the resource retaining timer, andsends a Data Path Rel Req to the relay DPF on the MSS link. The DataPath Rel Req carries: MSS ID, actual paging parameters (selected PG ID,paging cycle, paging offset, and PC ID), and idle mode authorizationindication;

(10) The relay DPF on the link forwards the Data Path Rel Req message tothe anchor DPF/FA. The anchor DPF/FA responds to the request message,releases the data path and replies with a Data Path Rel Rsp message tothe PA/SBS; and

(11) After receiving the Data Path Rel Rsp message, the PA/SBS confirmssuccess of entering the idle mode. Through a relay DPF, the PA/SBSreplies with a Data Path Rel Ack message to the FA, indicating that theMSS enters the idle mode successfully. The relay PC will delete theinformation on the MSS. Meanwhile, the FA sends a MSS Info Ack messageto the anchor PC, confirming completion of the MSS entering the idlemode. The anchor PC finally finishes data update in the LR. Upon expiryof the resource retaining timer, the PA/SBS deletes the information onthe local MSS.

The process shown in FIG. 5 can implement the functions of the processshown in FIG. 4.

The practical application also involves another scenario: if multiplehosts are attached to a MSS, when the network is initialized to enablethe MSS to enter the idle mode, the MSS may need to wait for aCMD_Duration before entering the idle mode due to interaction with thehost. After expiry of the CMD_Duration, the process of entering the idlemode will be initiated again. The detailed procedure is as follows:

a. The first step and the preceding operations are the same as thecounterpart of the foregoing two embodiments;

b. In the second step, the MSS decides to enter the idle mode only afterexpiry of a CMD_Duration, according to the actual conditions, and,hence, replies with a DREG_REQ message, which carries an action code“0x02” and the CMD_Duration information. After receiving this message,the network-side SBS stops the pre-set resource retaining timer if sucha timer is set previously when the SBS sends a DREG_CMD to the MSS; andwaits for the MSS to send a request of entering the idle mode; and

c. After a CMD_Duration expires, the MSS sends a new DREG_REQ,requesting to enter the idle mode. The subsequent steps are the same asthe counterpart steps in the foregoing embodiment.

The CMD_Duration parameter is newly added in the air interface message,DREG_REQ message, in the prior art, and is designed to notify thenetwork to wait for a CMD_Duration before the MSS enters the idle mode.

An alternative process of this embodiment is shown in FIG. 7. Unlike theprocess shown in FIG. 6, this process separates the transfer of MSSinformation from the release of the data path; and the MSS informationand paging-related parameters are transferred through MSS Info Req/MSSInfo Rsp messages. The functions implemented by the process are thesame.

It should be noted that the relay PC is optional in the foregoing step.If the relay PC does not exist, the PA/SBS will communicate with the FAdirectly.

In the foregoing embodiments, the process of the network enabling theMSS to enter the idle mode involves several relevant parameters, such asIdle Mode Timeout, Paging Interval Length, and Paging Cycle Req. TheDREG_REQ message of the MSS may carry one or more parameters, so thatthe parameters are transferred and stored into the anchor PC.

Regarding the Idle Mode Timeout parameter, after the MSS enters the idlemode, both the MSS and the PC will start an idle mode timer at the MSSside, upon expiry of which the MSS will initiate location update; or, inthe PC, start an idle mode system timer, upon expiry of which the PCwill initiate paging to the MSS to require location update if the PCreceives no location update request from the MSS, or will delete thecontext information of the MSS directly if the PC believes that the MSSis off network. The Idle Mode Timeout parameter is used by the MSS andthe PC to set the foregoing timers, and is negotiated by the MSS and thenetwork side in the process of registering the MSS onto the network.

In the process of the MSS entering the idle mode, the Idle Mode Timeoutparameter needs to be transferred and stored in the anchor PC for thepurpose of setting the idle mode system timer. If the anchor PC ismigrated when the MSS is in the idle mode, the parameter needs to betransferred to the new anchor PC. For that purpose, the Idle ModeTimeout parameter needs to be transferred to the current network sideduring the handover, including the target BS. This parameter isnegotiated in the process of registering the MSS onto the network; andthe BS or serving network that serves the MSS when the MSS accesses thenetwork may be different from the BS or serving network that serves theMSS when the MSS enters the idle mode later. Therefore, this parametermust be transferred together with the MSS context during the handover ofthe MSS.

Moreover, this parameter can also be configured by the network sidedirectly, and carried in the DREG_REQ message to the MSS, without beingnegotiated in the process of registering the MSS onto the network.

Regarding the Paging Interval Length parameter, according to the pagingcycle and the paging offset, it is practicable to calculate the specificradio frame (Nframe), after which the BS begins to send paging messages.The Paging Interval Length refers to the number of continuous frames (N)starting from Nframe, where N is not Nframe. Namely, the MSS can receivethe paging messages in N continuous frames starting from Nframe, afterthe paging message occurs. The Paging Interval Length parameter is alsodetermined through negotiation with the network side in the process ofregistering the MSS onto the network.

In the process which the MSS entering the idle mode, the Paging IntervalLength parameter needs to be transferred and stored in the anchor PC;and needs to be transferred to the BS when the anchor PC initiatespaging for the purpose of determining the scheduling policy of sendingthe paging message. If the anchor PC is migrated when the MSS is in theidle mode, the parameter needs to be transferred to the current networkside, including the target BS. This parameter is negotiated in theprocess of registering the MSS onto the network; and the BS or servingnetwork that serves the MSS when the MSS accesses the network may bedifferent from the BS or serving network that serves the MSS when theMSS enters the idle mode later. Therefore, this parameter must betransferred, together with the MSS context during the handover of theMSS.

Regarding the Paging Cycle Req parameter, it is carried in the DREG_REQmessage in the process of the MSS entering the idle mode, and serves asa basis for the network side to determine the paging cycle for this MSS.Therefore, in the process of the MSS entering the idle mode, thisparameter needs to be carried to the PC.

Regarding the MAC Hash Skip Threshold parameter, it is a threshold of anumber of continuously sent paging messages (MOB-PAG-ADV). If no pagingmessage specific to the MSS exists among a set number (threshold) ofpaging messages that are sent continuously, the PC or PA/BS will send apaging message specific to the MSS. Therefore, the MAC Hash SkipThreshold parameter needs to be transferred and saved into the PC sothat the PC or PA/BS can handle accordingly in the case that theconditions are fulfilled. This parameter may be determined throughnegotiation with the network side in the process of registering the MSSonto the network, carried in the MSS Info Req message or the DREG_REQmessage, and, hence, transferred and stored into the relay PC or anchorPC.

The Idle Mode Timeout, Paging Interval Length, Paging Cycle Req, and MACHash Skip Threshold parameters mentioned above can be configured by thenetwork side uniformly, so that they will vary with the terminal. Inthis case, they are not necessarily transferred in the process of theMSS entering the idle mode in an embodiment of the present invention.

Regarding the Paging Preference parameter, every service flow created bythe MSS has a Paging Preference parameter. If this parameter is set, itmeans that the network can generate a paging message to page the MSSafter the MSS enters the idle mode if the service flow has an incomingdownlink packet; if this parameter is not set, the network will notgenerate a paging message to page the MSS when the service flow has anincoming downlink packet; when a downlink packet of the MSS arrives butfinds no corresponding service flow, the anchor PC may initiate or maynot initiate the paging to the MSS, according to the presetting.

After the MSS enters the idle mode, the network will retain only theservice flow information who's Paging Preference is set to 1, if the 7thbit of the Idle Mode Retain Information parameter is set to 1. For otherservice flow information the anchor DPF/FA will delete the service flowinformation which is not to be retained, and notify the Service FlowAuthorization (SFA) entity and the Policy Function (PF) entity to deleteand release the service flows, after the MSS enters the idle mode. Theinformation stored in the anchor PC/LR may include the service flowinformation of the MSS for which a Paging Preference parameter is set,and exclude the service flow information for which no Paging Preferenceparameter is set.

Like in the foregoing embodiments, the anchor PC must record thefollowing information into the context carried in the request ofentering the idle mode sent by the MSS: ID of the current anchor DPF/FA(which may be IP address of the ASN GW that contains the anchor DPF/FA),and the anchor authenticator ID.

The anchor authenticator of the MSS must record the anchor PC ID whichexists when the MSS is in the idle mode. The anchor PC ID may berecorded when the anchor PC consults the anchor authenticator whetherthe MSS can enter the idle mode; or the anchor PC notifies the anchor PCID to the anchor authenticator of the MSS, after confirming that the MSSenters the idle mode.

Moreover, the anchor DPF/FA records the anchor PC ID of the MSS. Forthis purpose, the anchor PC may notify the anchor PC ID to the anchorDPF/FA of the MSS, after confirming that the MSS enters the idle mode.

Although the WiMAX system is used as an example in describing thetechnical solution under the present invention, the technical solutionunder the present invention is not limited to the WiMAX system, but isapplicable to other wireless MANs, such as 802.20-based wireless MANs.

As analyzed above, the method under the present invention enables thenetwork side to send a request of getting the MSS into the idle mode,thus standardizing and perfecting the process of the MSS entering theidle mode and making the process more stable.

The embodiments described above are only preferred embodiments of theinvention and are not intended for limiting the invention. Anymodification, equivalent substitution, and improvement without departingfrom the spirit and principle of this invention shall be covered in theprotection scope of the invention.

1. A method for a network side to enable a MSS to enter an idle mode ina wireless MAN, comprising: sending, by a PA/SBS, a DREG_CMD message tothe MSS; receiving, by the PA/SBS, a DREG_REQ message indicating thatthe MSS has entered the idle mode, from the MSS; sending, by the PA/SBS,a Data Path Rel Req message requesting to release a data path of theMSS; and updating, by an anchor PC/LR, idle mode information of the MSS,after receiving the DREG_REQ message.
 2. The method of claim 1, furthercomprising: sending, by the PA/SBS, an MSS Info Req message to a RelayPC; specifying, by the Relay PC, the anchor PC/LR in response to the MSSInfo Req message; allocating, by the Relay PC, recommended pagingparameters for the MSS in response to the MSS Info Req message; andsending, by the Relay PC, the MSS Info Req message carrying the pagingparameters to the anchor PC/LR.
 3. The method of claim 2, furthercomprising: sending, by the anchor PC/LR, a message to an anchorauthenticator of the MSS in response to the MSS Info Req message fromthe Ralay PC, in order to inquire whether the MSS is allowed to enterthe idle mode; and responding, by the anchor authenticator, to theanchor PC/LR, indicating whether the MSS is allowed to enter the idlemode or not.
 4. The method of claim 3, further comprising: storing, bythe anchor authenticator of the MSS, the idle mode information of theMSS, which includes an ID of the anchor PC, an ID of an anchor DPF,and/or security context information.
 5. The method of claim 1, furthercomprising: deciding, by the network side, whether the MSS is allowed toenter the idle mode.
 6. The method of claim 1, further comprising:sending, by the PA/SBS, an MSS Info Req message to a Relay PC;recommending, by the Relay PC, the anchor PC/LR and paging parametersfor the MSS in response to the MSS Info Req message; and sending, by theRelay PC, an MSS Info Req message carrying the paging parameters to theanchor PC.
 7. The method of claim 6, further comprising: sending, by theanchor PC/LR, a message to an anchor authenticator of the MSS inresponse to the MSS Info Req message from the anchor PC/LR, in order toinquire whether the MSS is allowed to enter the idle mode; andresponding, by the anchor authenticator, to the anchor PC/LR, indicatingwhether the MSS is allowed to enter the idle mode or not.
 8. The methodof claim 7, further comprising: storing, by the anchor authenticator ofthe MSS, the idle mode information of the MSS, which includes an ID ofthe anchor PC, an ID of an anchor DPF, and/or security contextinformation.
 9. The method according to claim 1, after the PA/SBSsending a Data Path Rel Req message requesting to release a data path ofthe MSS, further comprising: storing, by a DPF/FA associated with theMSS, information carried in the Data Path Rel Req message afterreceiving such a message and forwarding the message to the anchor PC/LR;retaining, by the anchor PC/LR, the corresponding information, andsending a MSS Info Rsp message to the DPF/FA, with an idle modeauthorization indication and the actual paging parameters carried in themessage; replying, by the DPF/FA, with a Data Path Rel Rsp to thePA/SBS, after receiving the MSS Info Rsp message; sending, by thePA/SBS, a DREG_CMD message to the MSS, after confirming success ofentering the idle mode; sending, by the PA/SBS, a Data Path Rel Ackmessage to a FA to confirm release of the data path; and sending, by theFA, a MSS Info Ack message to the anchor PC/LR.
 10. The method accordingto claim 1, after the PA/SBS sending a Data Path Rel Req messagerequesting to release a data path of the MSS, further comprising:receiving, by the anchor PC/LR, the MSS Info Req message being forwardedthrough an anchor DPF/FA associated with the MSS; retaining, by theanchor PC/LR, the corresponding information, and replying with a MSSInfo Rsp message to the PA/SBS, with an idle mode authorizationindication and the actual paging parameters carried in the message;sending, by the PA/SBS, a DREG_CMD message to the MSS, after receivingthe response message; sending, by the PA/SBS, a Data Path Rel Reqmessage to the anchor DPF/FA; responding, by the anchor DPF/FA, to theData Path Rel Req message, releasing the data path and replying with aData Path Rel Rsp message to the PA/SBS; sending, by the PA/SBS, a DataPath Rel Ack message to the DPF/FA, after receiving the Data Path RelRsp message; and sending, by the anchor DPF/FA, a MSS Info Ack messageto the anchor PC/LR.
 11. The method of claim 1, further comprising:initiating, by the PA/SBS, a resource retaining timer; and deleting, bythe PA/SBS, information related to the MSS, when the resource retainingtimer is expired.
 12. The method of claim 1, wherein: after the MSSenters the idle mode, if the anchor PC/LR has stored the correspondingservice flow information, and a Paging Preference parameter has been setfor the service flow, and when all downlink service flows of the MSSarrive, the anchor PC/LR initiates paging to the MSS.
 13. The method ofclaim 2, wherein: the MSS Info Req message or the DREG_REQ messageincludes an Idle Mode Timeout parameter, the anchor PC/LR triggering anIdle Mode System Timer, according to the Idle Mode Timeout parameter,after the MSS enters the idle mode; and when the timer is expired, theanchor PC/LR initiates paging to the MSS or delete the contextinformation of the MSS directly, if the anchor PC/LR receives nolocation update request from the MSS.
 14. The method of claim 2,wherein: the paging parameters carried in the MSS Info Req message orthe DREG_REQ message are selected from the group consisting of a PagingInterval Length parameter, a Paging Cycle Req parameter and a MAC HashSkip Threshold parameter, which is transferred and stored into the relayPC or anchor PC/LR.
 15. The method of claim 6, wherein: the MSS Info Reqmessage or the DREG_REQ message includes an Idle Mode Timeout parameter,the anchor PC/LR triggering an Idle Mode System Timer, according to theIdle Mode Timeout parameter, after the MSS enters the idle mode; andwhen the timer is expired, the anchor PC/LR initiates paging to the MSSor delete the context information of the MSS directly, if the anchorPC/LR receives no location update request from the MSS.
 16. The methodof claim 6, wherein: the paging parameters carried in the MSS Info Reqmessage or the DREG_REQ message are selected from the group consistingof a Paging Interval Length parameter, a Paging Cycle Req parameter anda MAC Hash Skip Threshold parameter, which is transferred and storedinto the relay PC or anchor PC/LR.
 17. A communication system,comprising a Relay PC and a PA/SBS, wherein: the PA/SBS is configured tosend a DREG_CMD message to a MSS; the PA/SBS is also configured to senda Data Path Rel Req message requesting to release a data path of the MSSin response to a DREG_REQ message indicating that the MSS has entered anidle mode from the MSS; and the Relay PC is configured to specify ananchor PC/LR and allocate recommended paging parameters for the MSS, inresponse to a MSS Info Req message.
 18. The system of claim 17, furthercomprising: an anchor PC/LR which is configured to update idle modeinformation of the MSS after receiving the DREG_REQ message.
 19. Apaging agent which is communicating with a MSS in a wireless MAN,configured to: send a MSS Info Req message to a Relay PC; receive a MSSInfo Rsp message from the Relay PC; send a DREG_CMD message to the MSS;receive a DREG_REQ message from the MSS; and send a Data Path ReleaseRequest message to request for releasing a data path of the MSS, whenthe REG_REQ message from the MSS indicates that the MSS has entered orwill enter an idle mode.